EMBA programmes must meet certain criteria in order to be considered for the ranking. The schools must be accredited by either the US’s Association to Advance Collegiate Schools of Business or the European Equis accreditation bodies. Their programmes must also have run for at least four consecutive years.

This year, 129 programmes took part in the ranking process, including 16 delivered jointly by more than one school.

Data for the ranking are collected using two online surveys: one completed by participating schools and one by alumni who graduated from their nominated programmes in 2012.

For schools to be ranked, 20 per cent of their alumni must respond to the survey, and there must be 20 fully completed responses. A total of 4,610 alumni completed the survey — 49 per cent of participants.

Alumni responses inform five ranking criteria: “salary today”, “salary increase”, “career progress”, “work experience” and “aims achieved”. They account together for 55 per cent of the ranking’s weight. The first two criteria about alumni salaries are the most heavily weighted, each counting for 20 per cent.

Salaries of non-profit and public sector workers, as well as full-time students, are removed. Remaining salaries are converted to US dollars using the latest purchasing power parity (PPP) rates supplied by the International Monetary Fund. The very highest and lowest salaries are subsequently removed and the mean average “current salary” is calculated for each school.

“Salary increase” is calculated for each school according to the difference in average alumni salary before the EMBA to three years after graduation, a period of typically four to five years. Half of this figure is calculated according to the absolute increase and half according to the percentage increase relative to pre-MBA salaries.

Where available, data collated by the FT for the two previous rankings are used for all alumni-informed criteria. Responses from the 2015 survey carry 50 per cent of the total weight and those from 2014 and 2013 each account for 25 per cent. Excluding salary-related criteria, if only two years of data are available, the weighting is split 60:40 if data are from 2015 and 2014, or 70:30 if from 2015 and 2013. For salary figures, the weighting is 50:50 for two years’ data, to negate any inflation-related distortions.

Information provided by the business schools themselves inform the next 10 criteria that collectively account for 35 per cent of the final ranking. These measure the diversity of teaching staff, board members and EMBA students, according to gender and nationality, as well as the international reach of the programme. For gender-related criteria, schools that have a 50:50 (male:female) composition receive the highest possible score.

In addition to the percentage of schools’ students and faculty that are international, the composition of these groups by individual citizenship informs a diversity-measuring score that feeds into the calculation.

The final criterion, the FT research rank, accounts for 10 per cent of the ranking. It is calculated according to the number of articles published by schools’ full-time faculty in 45 internationally recognised academic and practitioner journals. The rank combines the absolute number of publications, between January 2012 and August 2015, with the number of publications weighted relative to the faculty’s size.

The FT ranking is a relative ranking. Schools are ranked against each other by calculating a Z-score for each criterion. Z-scores represent the number of standard deviations each school’s data is away from the mean. Z-scores allow the ranking to be based on very different criteria (salary, percentages, points) since they are unitless. These scores are then weighted as outlined in the ranking key and added together for a final score.

After removing the schools that did not have a sufficient response rate from the alumni survey, a first version is calculated using all remaining schools. The school at the bottom is removed and a second version is calculated. This action is repeated until we reach the top 100. The top 100 schools are ranked accordingly to produce the 2015 list.

Key to the 2015 rankings

Weights for ranking criteria are shown in brackets as a percentage.

Salary today US$ (20): average salary three years after graduation, US$ PPP equivalent.†

Salary increase (20): average difference in salary between before the EMBA and now. Half of this figure is calculated according to the absolute salary increase and half according to the percentage increase relative to the pre-EMBA salary — the figure published in the table.†

Career progress (5): calculated according to changes in the level of seniority and the size of company alumni work in now, versus before their EMBA.†

Work experience (5): a measure of the pre-EMBA experience according to the seniority of positions held, number of years in each position, company size and overseas work experience.†

Aims achieved (5): the extent to which alumni fulfilled their goals or reasons for doing an EMBA.†

Female faculty (3): percentage of female faculty. For the three gender-related criteria, schools that have 50:50 (male:female) composition receive the highest possible score.

Female students (3): percentage of female students on the programme.

Women on board (1): percentage of female members of the advisory board.

International faculty (5): calculated according to the diversity of faculty by citizenship and the percentage whose citizenship differs from their country of employment — the published figure.

International students (5): the percentage of current EMBA students whose citizenship and country of residence differs from the country in which they study, as well as their diversity by citizenship.

International board (2): percentage of the board whose citizenship differs from the country in which the business school is situated.

International course experience (5): percentage of classroom teaching hours that are conducted outside the country in which the business school is situated.

Languages (1): number of languages required upon graduation.

Faculty with doctorates (5): percentage of full-time faculty with a doctoral degree.

FT doctoral rank (5): calculated according to the number of doctoral graduates from each business school during the past three years. Additional points are awarded if these graduates took up faculty positions at one of the top 50 full-time MBA schools of 2015.

FT research rank (10): calculated according to the number of articles published by a school’s current fulltime faculty members in 45 academic and practitioner journals between January 2012 and August 2015. The rank combines the absolute number of publications with the number weighted relative to the faculty’s size.

† Includes data for the current year and the one or two preceding years where available.

Judith Pizer of Jeff Head Associates acted as the FT’s database consultant